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so asto prevent springing and tremor, andere geared together by means of equal wheels, so as to secure the constant return to each other of the corresponding points in both the dies..

These spindles are arranged parallel with eachother, and at such'distance apart as will enable the threads Y. upon the dies to penetrate theblank bolt 4to their full depth on both its opposite sides; and that this shall be.

done with the necessary exactness, the bearings of the spindles, oroi one of them, should be Vsoeonstrncted aste be set closerto or further from each other, as may be required; and they should also be made adjustablel endwise, s as to secure the'exact coaptation of .the threads.

" The machine,th`us constructed, and geared, is set inmotion4 at a proper speedyby power 'from any tiret mover. A heated blank is then inserted in the socket or guide M, between the 'two dies AA', at the groove This being' done, the embossed portions 7c It of the dies, immediately'act upon the surface of the blankbolt,

causing it to rotate upon its own -axiswithin the socket Mand at the same time cracking off and removing they scale which has been formed upon the blankvby the'heating process.

I The embossed portion 'of the dies having passed `over the cir'cumfe'xenceof'the blank boltthe thread 1-v strikes into the substance of `the revolving blank, to-i'ts full depth, andthe blank having completed a revolution p `upon itsi-axis, thread 2 strikestinto the crease or'helical groove made by thread 1 YA second revolution of the blaukbeing completed, thread 3 strikes'into the` groove just' left by thread 2, thread 2 again entering and folldwinginto the groove lef-t' by thread '.L, and so on., for any number of threads. The `first .thread of the series may be considered as roughing out the helical crease or groove between the threads upon the bolt, and the suc'- ceeding threads as nishing such threads and spaces; but at the same time'they perform the important function fof preserving the true form of thethread upon the bolt,for the action of a single thread upon cach of the dies would beto spread the metalof' the blank, which has been displaced from the crease-or groove formed by it, to

,both its sides, butthis is ell'ect'ually prevented by'the 4succeeding threads of the dies, 'their conjoint action beingV to force the displaced metal to one side only of the first thread, that is, towards the pointvof the blank, the

consequence of which is, that the metal thus displaced from' between'the ythreads is worked `into thc `substance of' the bolt, thus utilizing the material by increasing thelength of the screw.

Having thus described the nature and construction of my improved screw-'forming dies,` and shown one of the modes in which they may bc applied to the production of'a useful ,eli'ectfwhatl I claim' therein as my own invention,land desire to secure by Letters Patent, is 'Y 1. Arrangingthe cutting-threads'on the surface of the dies, as herein described, thntis' tosay, sb-that-a portion of. cach of sa'id 'die-surfaces shall be left plain, forthe purpose of gradually rounding the blank, V:lathe operation of threading it progrcssesfand that thcrinitial or commencing portions of thescveral cutting-threads shall follow one another in succession, allsubstantially as set forth.

and for the purpose set forth. v BENJ'N D. BEECHER.

Witnesses:

H. ItrBaAnLsY, HENRY M. Buscemi.

2. I claim, in combination .with the threaded part of the die, the embossed surface k 7c', substantially as 

